Manufacturing operations are becoming increasingly automated. A significant factor in increasing such automation is the use of robots to perform repetitive tasks that require multiple, high-precision movements. Another factor favoring the use of robots is that a robot can perform a machining task in an environment, or using tools, that may pose a risk to humans. For example, a robot may be used to perform a machining operation that utilizes a plasma torch to cut metal such as steel. The use of a plasma torch generates extremely high temperatures, electric arcs, noxious gases, and a spray of molten metal.
There are several forms of robot devices that may be used to perform machining tasks. In one form, a machining tool, such as a plasma torch, an arc welder, or other device, may be mounted on an end of a machining tool that is moved by rails oriented at right angles to each other to move the machining tool in an X-Y direction, so that the machining operation follows a pattern in the form of Cartesian coordinates. An advantage of such a system is that it is relatively inexpensive, and can be repaired relatively quickly.
A robot also may take the form of a robotic arm. Such robotic arms may be computer controlled and include an end effector, which may be a plasma torch, connected to a swivel base by articulated segments. The swivel base and articulated segments give the robot arm flexible movement in three dimensions. However, such robotic arms are limited in reach to the collective length of the articulated arm segments. Such articulated robotic arms may be mounted on a gantry so that the robot arm itself may be displaced along the gantry rail to provide added reach, or to perform a task in more than one workspace. The size of a workpiece that may be operated on may be limited by the size of the gantry and the reach of the robotic arm.
Accordingly, there is a need for a gantry robot system that provides maximum flexibility of positioning of the end effector of the robot arm, and can accommodate a wide range of workpiece sizes within a minimal footprint.